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This invention brings together an electric door chime, its transformer and an enclosure that combines them all into one assembly.
Chimes (doorbells) have been installed in living units for most of the last century. While these have been effective enough in signaling occupants of these dwellings, the process of installation has changed through the years. The National Fire Protection Association and its electrical code body, NEC, have regulated installations of chime (doorbell) systems with equipment bearing the Underwriters Laboratory seal of approval. These systems were very fragmented due to the location requirements of the NEC. Bell transformers needed to be mounted to an electrical box so that they were on the outside and their 120 volt wires (Primary side) were in the inside where they could be spliced to the 120 volt source of power. The big problem for this was the location of these splice boxes. All splice boxes are required to be accessible, and the bell transformer was required to be accessible also. With finished walls and ceilings in dwelling units, there remained only two areas of accessibility. These areas were the attics and the basements or crawl spaces under the floor.
FIG. 15 shows a typical attic installation on a 4xe2x80x3 octagon metal splice box. The larger white wire is what electricians refer to as Romex. This is the source of 120 volt power. The two smaller brown wires are 24 volt rated wire and take the lower voltage produced on the secondary side of the transformer to the chime (doorbell). Additional 24 volt wire must be run from the bell to the doorbell buttons at the front and back doors of the living units.
FIG. 16 shows a typical wall location for the chime. One of the gray wires is going to the transformer while the other is going to the doorbell button. When the wall board is installed the only thing that will be seen is the loop of gray wire sticking out of the wall. The chime is hooked to these wires and then screwed to the wall. If backing is not placed in the wall then the chime is only screwed to the Sheetrock, which is not very substantial.
FIG. 17 shows details of a common chime location in front of a black 2 gang plastic box. The three bell wires going into this box are the lead from the transformer, the lead from the back door button and the lead from the front door button. It was the electrician""s intent to set the transformer in this box, but the installation was rejected because it did not meet code. Afterwards he relocated the transformer remotely, and ran the low voltage wire back to the box.
FIG. 18 shows a 2 gang plastic box which originally had the transformer mounted inside of it along with the 120 v and 24 v wire. The chime was unscrewed from the wall where it was covering the box, because the inspector was suspicious about its compliance with code. When the chime was swung to the side it revealed that the transformer was indeed placed in the box behind the chime.
FIG. 19 shows the new location of the transformer mounted on the other side of the wall.
FIGS. 20 and 21 show accessible locations for bell transformers in basement furnace rooms.
FIG. 22 shows an attempt to install a transformer in an accessible place. The transformer will be attached to the bottom of the electrical panel behind the plaster ring. The 120 v wire will be inside of the panel and the 24 v wire and the transformer will be in side the wall below the panel. This is a legal installation. It is an awkward place to install the transformer and requires a blank 2 gang plate to cover it. The blank plate does not make a pretty installation. The hand hole provided by the 2 gang plaster ring does not allow much room for grasping the transformer if a change out is required.
FIG. 23 shows the chime location in the hallway of this apartment. The wires will be connected to the back of the chime and then the chime will be screwed to the Sheetrock. As you can see there is no backing provided for the chime screws.
FIG. 24 shows process controls fed by low voltage wires (24 v). These wires are taped off from surface mounted transformers. Because access is required for the transformers and given the restrictions of mixing class 1 and class 2 wire together, there is presently no other way to make this installation. There is no prior art the could be used to eliminate this problem. What is available is not designed for the purpose and would be much more expensive. Large surface mounted enclosures are available but would only add to the bad looks of this installation.
Accordingly, besides the objects and advantages of the chimes and transformers found in industry today, several objects and advantages of my present invention are:
1. to provide a means of placing a doorbell transformer in a common and accessible location. This will become an industry standard.
2. the mounting of the transformer in a metal box to provide proper support for and adequate heat dissipation as will be required by UL.
3. this assembly will meet the requirements of the NEC.
4. the chime which will be part of this assembly, will mount to the metal box without screws. Wire springs will mate with 2 slots in the box and pull the chime up tight to the box.
5. the box will be a housing for the transformer and will have separate areas for the low voltage wire and the high voltage wire. It is also the mounting base for the chime.
6. the chime will completely cover the flush mounted back box when it is pushed tight against the wall. The normal person will not know that the back box is even there.
In accordance with the present invention, the Speedie-Chime comprises an assembly of a chime, a back box, and a transformer. The mounting of the chime and transformer to the back box, satisfies the requirements of the NEC and can be UL approved. The Speedie-Chime brings together these components which up till now could not be brought together in a manner that would meet NEC codes.